Psychosocial treatments are efficacious adjunctive treatments for persons with bipolar disorder. The use of internet platforms to deliver education and support for psychiatric disorders is increasingly common, but there is limited systematic research on the benefits of such programs. Internet based interventions have the potential to offer unlimited supportive resources with immediate access, minimal cost, convenience and flexibility. MoodSwings 2.0 is the next evolution of an internet-based intervention for individuals with bipolar disorder (www.moodswings.net.au), and is based on a validated face-to-face intervention, the MAPS project, which includes elements of psychosocial interventions including CBT, IPSTRT, psychoeducation, motivational interviewing, problem solving, goal setting, early warning signs and relapse prevention plans. Modules of MoodSwings 2.0 include symptom and disorder information as well as an asynchronous moderated peer discussion board. The program includes many interactive tools to optimize comprehension and retention of module content. MoodSwings 2.0 represents a significant improvement to earlier beta tested versions, with an improved platform, increased user navigation and interactive tools, and additional features designed to facilitate greater interest and interaction with program content. The program is not intended to serve as primary care for individuals with bipolar disorders. The proposed study includes the revision of MoodSwings 2.0, and a 12-month assessment of its use and benefits in patients with bipolar disorder. We propose a 2-site, 3-arm randomized parallel group stepped design (exposure to moderated peer discussion board only, discussion board plus psychoeducation, or discussion board, psychoeducation, and online interactive psychosocial tools). The collaborative sites (Palo Alto, CA and Melbourne, Australia) will enroll 300 participants with SCID-confirmed diagnoses of bipolar disorder I, II, or NOS. Interaction with research staff will occur through phone interviews and email correspondence, as participants will be recruited from any geographic location, providing inclusion criteria are met of a bipolar diagnosis, age 21-65, computer access, and local health care consisting of at least 2 provider visits in the past year and local emergency care. Exclusions are limited to current manic or psychotic symptoms. Utilization of the online MoodSwings 2.0 program is voluntary, and the program captures time spent in each content area over 12 months as an outcome of interest. Outcomes are assessed at quarterly intervals via phone interview with raters blind to group assignment as well as online self report. The primary outcome is the change in depressive symptoms over 12 months, assessing if there is additive benefit to the three components (education, discussion board, and interactive psychosocial tools) on improvement. Exploratory aims include symptoms of elevated mood, health services utilization, evidence of relapse (time to intervention), function, quality of life and medication adherence. PUBLIC HEALTH RELEVANCE: It is increasingly difficult for psychiatric patients to access care that includes education about their symptoms and illness, ways to manage and prevent episodes, and psychosocial support, despite evidence that this improves outcomes. Consequently, it is essential to explore the utility of the internet as a potential source of high quality, evidence based, supportive interventions that have minimal cost, convenience, and flexibility. The proposed study is a two-site international collaboration that will conduct a randomized trial of interest in, use of, and benefits of an internet-based psychoeducational and supportive intervention for 300 individuals with bipolar disorder (MoodSwings 2.0).